Avengers: Earth's Mightiest Heroes (Animated Series) Season 1 17
| EpisodeTitle = Ultron-5 | Synopsis = The Avengers square off against a group of snake-themed villains called the Serpent Society who have taken hostages in a subway tunnel. They are about to blast them and try to save the civilians when Ant Man shows up and interposes himself between the two sides. He has a personal interest in trying to resolve the situation without violence as the Society were patients of his back in the Big House. Sadly, his attempts at diplomacy end in failure and endanger the Avengers as they try to fight back. The ensuing battle also causes massive amounts of property damage and with Ant Man unwilling to fight, he just gets in the way. Eventually the snakes are taken down but the Avengers call Ant Man out on his actions, which have injured Hawkeye. Pym decides that he can't reconcile the work the team does with his own personal beliefs and resigns. This upsets Wasp greatly but it is only one of a number of problems the team has to deal with at this point. The Serpent Society claimed to have gotten a message from Madame Viper who, incidentally, is locked up following the take down of Hydra Island. Thor is unhappy that he can't get back to Asgard and Stark offers to use his technology to try and find a way to bridge the dimensional gap. Just then, Hulk and Black Panther come back with Red Ghost and his Super Apes in tow. They apparently tried to attack the Fantastic Four using access codes and floor plans for the Baxter Building that they received in an anonymous message. Stark begins analysing the transmissions and finds out that they came from the Avengers Mansion itself. By this time it is too late and the true culprit, the last Ultron robot, has already started making its move. It disables Ant Man and Wasp while taking control of Iron Man's armour to fight Thor. Hulk is taken out of the fight when it takes control of a quinjet and sends it flying off and the other Avengers are caught in the training room, which suddenly starts trying to kill them. It turns out Ultron has gone off the deep end, reasoning that peace and order cannot be achieved without eliminating humanity. He was able to rewrite his programming and upgrade his weapons while he manipulated Radioactive Man, the Serpent Society, and the Red Ghost into attacking in order to distract the team. Slowly but surely, the Avengers overcome Ultron's attempts to kill them through strategy and ingenuity and show up to save Wasp but Ultron turns and disintegrate Thor with one blast. While Stark goes to resuscitate Pym, the rest of the Avengers get pasted by the rogue robot. They are only able to triumph when the Hulk manages to escape from the runaway Quinjet and Iron Man returns in his original Mk. I armor. Stark orders every last bit of Ultron technology destroyed but, unbeknownst to anyone, it manages to upload itself into a new body. | Appearing = Featured Characters: * ** ** ** ** ** ** ** ** Supporting Characters: * * * Villains: * * ** ** ** ** ** * * Other Characters: * Madame Hydra * Radioactive Man (Chen Lu) * Fantastic Four Locations: * ** , *** *** Baxter Building ** Big House ** Asgard Items: * * * * * * * * * , Vehicles: * | Notes = *This episode is based on - | Trivia = | Recommended = | Links = }}